Portable electronic devices, such as notebook computers, mobile phones, and personal digital assistants (PDAs), often include injection molded housings for protecting electrical components, such as antennae for receiving and/or transmitting communication signals, displays, etc. As the demand for thinner devices has increased, so has the demand for higher performance plastic materials that can be injection molded into the desired configurations. One such material is polyphenylene sulfide (“PPS”), which is a high performance polymer that can withstand high thermal, chemical, and mechanical stresses. PPS is generally formed via polymerization of p-dichlorobenzene with an alkali metal sulfide or an alkali metal hydrosulfide, forming polymers that include chlorine at the terminal groups. Nevertheless, a problem often experienced by conventional PPS compositions is that they contain a residual amount of chlorine from to the polymerization process. For portable electronic devices, however, the presence of a significant amount of chlorine is problematic due to environmental concerns. Attempts at eliminating the presence of chlorine have generally involved the use of higher molecular weight polymers having a low chlorine content. Unfortunately, such polymers also have a high melt viscosity, which makes them difficult to melt process and mold into thin parts. This problem is aggravated by the addition of fillers that can even further increase the melt viscosity of the composition.
As such, a need currently exists for a housing for a portable electronic device that contains a polyarylene sulfide having a relatively low melt viscosity and low chlorine content, while still providing good mechanical properties.